Lighting and Collision Alerting System

ABSTRACT

A collision avoidance system includes a sensor adapted to detect at least one vehicle in the vicinity of a predetermined area and generate target data relating to the at least one vehicle. An awareness engine receives the target data and evaluates the target data for a threat of a collision. An alerting system is adapted to alert the at least one vehicle in the event of a threat of a collision, the alerting system being activated by the awareness engine.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/641,290, filed Jul. 4, 2017, now U.S. Pat. No. 10,124,910, which is acontinuation of U.S. patent application Ser. No. 14/691,091, filed Apr.20, 2015, now U.S. Pat. No. 9,694,914, which is a continuation of U.S.patent application Ser. No. 13/596,203, filed Aug. 28, 2012, now U.S.Pat. No. 9,013,331, which is a continuation-in-part of U.S. patentapplication Ser. No. 13/423,483, filed Mar. 19, 2012, now U.S. Pat. No.9,010,969, which claims priority to U.S. provisional application No.61/453,944, filed Mar. 17, 2011, U.S. provisional application No.61/454,237, filed Mar. 18, 2011, and U.S. provisional application No.61/511,872, filed Jul. 26, 2011. The entire contents of each of theseapplications are expressly incorporated herein by reference thereto.

FIELD

The present invention relates generally to lighting systems, inparticular to obstruction lighting systems utilizing light emittingdiodes. The present invention further relates to collision alertingsystems usable in conjunction with, among other things, theaforementioned lighting systems.

BACKGROUND

The Federal Aviation Administration (FAA) requires that obstructions toaircraft navigation, such as towers, cables and tall buildings be fittedwith visibly perceivable elements to render these structures highlyvisible to approaching aircraft. FAA Advisory Circular 150/5345-43 formsa specification of technical requirements for these lights in the UnitedStates. Within Advisory Circular 150/5345-43 there exists a requirementfor a medium-intensity flashing red obstruction light system, designatedthe “L-864” and a medium-intensity flashing white obstruction light,designated the “L-865.” These obstruction lights are to be placed inaccordance with a set plan at levels on all obstructions that arepotential hazards to air navigation.

For the L-864 obstruction light, at all radials throughout a 360 degreeazimuth, there must be a peak effective intensity of 2,000±25 percentcandela. There must also be a minimum effective intensity of 750 candelathroughout a minimum vertical beam spread of 3 degrees. For the L-865obstruction light, at all radials throughout a 360 degree azimuth, theremust be a peak effective intensity of 20,000±25 percent candela duringoperation at day and twilight conditions, and 2,000±25 percent candeladuring night conditions. The L-865 obstruction light also includes aminimum vertical beam spread of 3 degrees.

A drawback of these obstruction lights is that they typically utilizeincandescent lamps, which have a relatively limited service life.Consequently, the incandescent lamps require frequent replacement. Sincethe obstruction lights are mounted atop tall structures, replacing theselamps can be inconvenient, time-consuming, expensive and even dangerous.Utilizing light emitting diodes (LEDs) as a light source in obstructionlights overcomes many of these drawbacks. However, LEDs present newdesign challenges.

Another drawback of conventional obstruction lights is light pollution.Light pollution as it relates to obstruction lighting may be generallydefined as the emission of light outside the band specified by AdvisoryCircular 150/5345-43. Light pollution can be an annoyance, particularlywhen the obstruction light is proximate to residential areas. In somecases light pollution can cause problems such as sleep deprivation orthe blocking of an evening view.

In an optical system for an obstruction light, one approach forarranging LED light sources is to orient them vertically, aimedoutwardly from the light assembly. However, shaping multiple lightsources into a tight continuous horizontal beam requires a lens, whichis less efficient than a reflector. Additionally, the LED junctionsthusly configured are more vulnerable to damage due to lightningeffects.

Another approach is to mount the LEDs so they are oriented horizontallyand aimed upwardly, using a reflector to shape and redirect the lightoutwardly. In this configuration the reflector is very efficient andalso acts as a lightning mediator. Another advantage of this arrangementis that it minimizes direct-light emissions from the LEDs shiningdownwardly from the obstruction light, which may be considered aneighborhood annoyance.

Orienting LEDs so that they are aimed downwardly is also desirable sinceit offers more efficient cooling of the LEDs and makes servicing of theLEDs more convenient. However, this arrangement is problematic becauseit inherently directs some of the LED light toward the neighborhoodbelow the obstruction light.

Moreover, horizontally orienting LEDs and aiming them toward a reflectoris undesirable, as this directs the brightest part of the LED beamtoward the flatter area of the reflector, thereby reducing beam focus.

In addition to obstruction lights, strobe lights and beacons (hereaftercollectively and generally termed “anti-collision lights”) are attachedto vehicles, and to obstructions such as buildings and communicationtowers. Anti-collision lights are designed to warn vehicle operators ofhazards to navigation, typically by periodically illuminating the lightin a repetitive, attention-getting on-and-off pattern. p Currentground-based anti-collision technology typically compriseshigh-intensity lights that may be configured to flash at predeterminedcolors, frequencies, and intensities. Their design is intended toprovide a visually perceivable alert to deter potential collisions.These lights have proven effective over time, but they have notsignificantly changed in almost eight decades. While anti-collisionlights have increased in intensity and visibility, become more reliableand energy efficient, and have developed the ability to report theiroperating condition (i.e., faults) and status, they have not evolvedbeyond simply flashing or blinking a light at a regular interval toprovide a simple warning. Since the light has no active role incollision avoidance, it is incumbent upon the operator of a vehicle inthe vicinity of the light to see it, recognize it, and reactappropriately to avoid a collision.

As population densities increase, the current anti-collision technologyis being stressed. The increasing population density creates threechallenges for the existing state-of-the-art flashing anti-collisionlight. Firstly, there is more traffic and population in a givengeographic region, which increases the potential for a collision.Secondly, more people require more infrastructure, which results in moreman-made obstacles being erected with which to collide. Finally, currenttechnology is increasingly becoming more dependent upon wirelessresources, resulting in an ever-increasing number of transmitting andreceiving towers that may become hazards to navigation. Growingpopulations, expanding infrastructure requirements, and evolvingwireless technologies are all resulting in a significant increase in thepotential for dangerous collisions while anti-collision technology haseffectively remained stagnant.

Furthermore, renewable-energy systems such as wind turbines are becomingincreasingly common. These systems, owing to their size, often presentpotential hazards to air navigation.

SUMMARY

An obstruction light utilizing LEDs as a light source is disclosedaccording to an embodiment of the present invention. The LEDs areoriented and aimed toward a reflector so as to minimizedownwardly-directed light while also enhancing the characteristics ofthe desired light output from the reflector.

One object of the present invention is a lighting system comprising areflector having a plurality of reflecting surfaces. The plurality ofreflecting surfaces have at least one optical axis, and the reflectingsurfaces further include a linearly projected cross-section along arespective linear axis. In one embodiment, the linearly projectedcross-section of the reflecting surfaces comprise a substantially conicshape. A plurality of light emitting diodes (LEDs) are positioned in aline generally parallel to the linearly projected cross-section of theplurality of reflecting surfaces. The LEDs are oriented relative to anassociated reflecting surface such that a central light-emitting axis ofthe plurality of LEDs is angled relative to the at least one opticalaxis of the associated reflecting surface at about 45°. The reflectingsurfaces redirect and collimate a light output of the plurality of LEDsat an angle of about 45° with respect to the central light emitting axisof the plurality of LEDs.

In one embodiment the present invention detects and tracks vehicles inclose proximity to a predetermined obstacle having a known location. Inthe event of a detected potential collision threat the present inventionreacts by directly alerting the vehicle in any suitable manner such as,but not limited to, radio communications, aural signals and visuallyperceivable signals such as a light having alterable operatingcharacteristics. So alerted, the operator of the vehicle can changecourse, as needed, to avoid the collision.

In another embodiment of the present invention a collision avoidancesystem includes a sensor that is configured to detect at least onevehicle in the vicinity of a predetermined area and generate target datarelating to the at least one vehicles. The system further includes anawareness engine that is configured to receive the target data from thesensor and evaluate the target data for a threat of a collision. Analerting system issues an alert to the at least one vehicle in the eventof a threat of a collision, the alerting system being activated by theawareness engine.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features of the inventive embodiments will become apparent tothose skilled in the art to which the embodiments relate from readingthe specification and claims with reference to the accompanyingdrawings, in which:

FIG. 1 is a perspective view of an obstruction light according toembodiment of the present invention;

FIG. 2 is a perspective view of an embodiment of an optic of theobstruction light shown in FIG. 1;

FIG. 3 is a partial sectional side view of an embodiment of the opticshown in FIG. 2;

FIG. 4 shows the angular relationship between an optical axis associatedwith a reflecting surface of the optic of FIG. 2, a central lightemitting axis of an LED of the optic, and a linear axis of thereflecting surface;

FIG. 5 describes optical characteristics of the optic of FIG. 2;

FIG. 6 is a sectional top view of a reflector of the optic of FIG. 2;

FIG. 7 is a partial side view of the optic of FIG. 2, showing simulatedlight ray traces;

FIG. 8 is a partial front view of the optic of FIG. 7, showing the samelight ray traces from another view;

FIG. 9 is a view in section of the obstruction light of FIG. 1;

FIG. 10 is a schematic block diagram showing the general arrangement ofa control system for an obstruction light according to an embodiment ofthe present invention;

FIG. 11 is a schematic block diagram of a collision avoidance systemaccording to an embodiment of the present invention;

FIG. 12 is a schematic block diagram of an awareness engine portion ofthe collision avoidance system of FIG. 11;

FIG. 13 shows an intelligent runway anti-intrusion system according toan embodiment of the present invention;

FIG. 14 shows a tower obstruction with a lighting and collision alertingsystem according to an embodiment of the present invention.

FIG. 15 is a schematic block diagram of a ground station for anAutomatic Dependent Surveillance-Broadcast (ADS-B) surveillance systemaccording to an embodiment of the present invention; and

FIG. 16 shows a tower obstruction with a lighting and collision alertingsystem according to another embodiment of the present invention.

DETAILED DESCRIPTION

The general arrangement of a lighting system 10 usable as an obstructionlight, among other purposes, is shown in FIG. 1 according to anembodiment of the present invention. Lighting system 10 comprises anoptic 12, a lens 14, a housing 16, a mounting base 18, an electricalconnection 20 to the lighting system, and circuitry (not shown) to drivethe lighting system. In one embodiment, a drive circuit (not shown) isdisposed within a housing 16 and is capable of strobing optic 12 at oneor more predetermined flash rates. Housing 16 supports optic 12, whichis coupled thereto, and mounting base 18 provides a means for attachinglighting system 10 to a structure.

FIG. 2 is a perspective view showing details of optic 12 according to anembodiment of the present invention. Optic 12 comprises a reflector 22having a plurality of reflecting surfaces 24 that form a segmented-typereflector. Reflector 22 may be any type of optical reflector suitablefor use with obstruction light 10. For example, reflector 22 may be,without limitation, in the form of a half-parabolic reflector.

With continued reference to FIG. 2, FIG. 3 depicts a partial sectionalside view of optic 12. Each reflecting surface 24 comprises across-section 26, projected along an associated linear axis 28. As canbe seen, reflecting surface 24 has a generally conic cross-section, anda central light-emitting axis 30 of a light emitting diode (LED) 32 isin the same plane as the cross-section. FIG. 3 also shows an angle θ₁over which light emitted from LED 32 is reflected by reflecting surface24. In one embodiment, the linearly projected cross-section 26 comprisesa conic section. In other embodiments cross-section 26 of reflectingsurface 24 comprises at least one of a conic or a substantially conicshape. In various embodiments the conic shape comprises at least one ofa hyperbola, a parabola, an ellipse, a circle, or a modified conicshape.

In some embodiments of the present invention reflecting surface 24 isneither concave or convex along linear axis 28. In other embodimentsreflecting surface 24 may be concave along linear axis 28. In stillother embodiments reflecting surface 24 may be convex along linear axis28.

Each reflecting surface 24 has an associated optical axis 34. In oneembodiment, each reflecting surface 24 reflects a beam of light havingan angular distribution that is horizontally symmetric to the associatedoptical axis 34, i.e., symmetric about the associated optical axis indirections along linear axis 28.

Reflector 22 may be made from any suitable material including, withoutlimitation, metal or a reflective material. Non-limiting examples ofmaterials for reflector 22 include highly-polished metal, a coated(i.e., “metalized”) metal or non-metal substrate, and a reflective filmapplied to a metal or non-metal substrate.

For each reflecting surface 24, optic 12 comprises at least oneassociated LED 32. LED 32 typically emits light in a hemisphere centeredand concentrated about central light-emitting axis 30. LED 32 ispositioned relative to the associated reflecting surface 24 such thatcentral light-emitting axis 30 of the LED is angled at a predeterminedangle θ₂ relative to the optical axis 34 associated with the reflectingsurface 24. In a preferred embodiment, θ₂ has a value of about 45°. Insome embodiments of the present invention, the about 45° value has atolerance of ±15°, i.e., from 30° to 60°.

With reference now to FIG. 4 in combination with FIGS. 2 and 3, in oneembodiment of the present invention, for a specific reflecting surface24 and associated LED 32, the central light-emitting axis 30 of the LED,the optical axis 34 associated with the reflecting surface, and thelinear axis 28 of the reflecting surface form axes of a 3-axis linearcoordinate system. θ₂ is the angle between central light-emitting axis30 and optical axis 34. θ₃ is the angle between optical axis 34 andlinear axis 28. θ₄ is the angle between the central light emitting axis30 and the linear axis 28. In one embodiment, the relationship betweencentral light-emitting axis 30, optical axis 34 and linear axis 28 isapproximate. For example, each of central light-emitting axis 30,optical axis 34, and linear axis 28 can be angled at 45° from each ofthe other two axes, with a tolerance, in some embodiments, of ±15°.

As shown in FIG. 2, for each reflecting surface 24, optic 12 includes aplurality of associated LEDs 32. In one embodiment, the plurality ofassociated LEDs 32 are arranged along a line, generally parallel tolinear axis 28 of reflecting surface 24. In other embodiments of thepresent invention the plurality of associated LEDs 32 may be generallystaggered about a predetermined line. For example, in one embodiment,the plurality of associated LEDs 32 are staggered about a line, with thestaggering comprising offsetting the LEDs from the line by apredetermined distance in alternating directions perpendicular to theline. As will be detailed further below, in some embodiments of thepresent invention LED 32 (or a plurality of LEDs) are positioned at afocal distance of reflecting surface 24.

FIG. 5 depicts a partial perspective view of an embodiment of lightingsystem 10 in which the lighting system emits light outward over a 360°angular distribution about a central axis 36 of the reflector 22 ofoptic 12. Such a 360° angular distribution of reflected light may be arequirement for lighting system 10 to provide obstruction warning in alldirections. The light emitted from the beacon light 20 has apredetermined beam spread θ₅. The beam spread θ₅ is the angle,vertically perpendicular to the optical axes 34 of the reflectingsurfaces 24, over which the intensity of the emitted light is greaterthan 50% of the peak intensity of the emitted light. In a preferredembodiment, lighting system 10 has a beam spread θ₅ of less than 3°. Inanother embodiment, lighting system 10 has a beam spread θ₅ of less than10°.

Referring again to FIGS. 2 and 3, the plurality of reflecting surfaces24 of reflector 22 are arranged such that each of the associated linearaxes 28 is angled relative to the linear axis of another reflectingsurface. In one embodiment, the plurality of linear axes 28 occupy asingle plane and intersect each other to outline a polygon. In otherwords, a top-view cross-section of reflector 22 may have a perimeterwhich is polygonal in shape. FIG. 6 depicts a sectional top view of anembodiment of reflector 22, showing the plurality of associated linearaxes 28 intersecting each other to form a hexagon. This embodiment ofreflector 22 achieves the aforementioned 360° angular distribution,relative to the central axis 36 of reflector 22, of light emitted fromoptic 12. Each reflecting surface 24 preferably reflects light in thedirection of the optical axis 34 associated with that reflectingsurface, and through an angular distribution horizontally symmetric toand centered to the optical axis.

Although FIG. 6 depicts a polygon embodiment of reflector 22 having sixreflecting surfaces 24 it will be understood that the reflector may havegreater or fewer reflecting surfaces within the scope of the invention.In addition, the intersection of the plurality of linear axes 28 neednot outline a polygon. Furthermore, light emitted from optic 12 need nothave a 360° angular distribution relative to the central axis 36 ofreflector 22. Such an embodiment may instead have, for example, a 180°angular distribution.

In some embodiments of the present invention the plurality of reflectingsurfaces 24 of reflector 22 may be connected together. Accordingly,reflecting surfaces 24 may be made as separate pieces and joinedtogether. Alternatively, reflecting surfaces 24 may be formed as aunitary piece.

FIG. 7 shows a partial side view of an embodiment of optic 12. LED 32 islocated at a focal distance “f” of reflecting surface 24. FIG. 7 alsoshows simulated ray traces 38 showing the path of light traveling fromLED 32 to reflecting surface 24 and outward from reflector 22. As can beseen, ray traces 38 are generally parallel to optical axis 34 of optic12.

FIG. 8 shows a partial frontal view of the optic 12 of FIG. 7, showingthe same simulated ray traces 38 as FIG. 7. Because reflecting surface24 of FIGS. 7 and 8 is a projection of the cross-section 26 along thelinear axis 28, light traveling from LED 32 to the reflecting surfaceresults in collimated light that is reflected generally parallel to theoptical axis 34 of reflecting surface 24.

A view in section of lighting system 10 is shown in FIG. 9 according toan example embodiment of the present invention. Reflector 22 is orientedsuch that a base portion 37 (FIG. 2) of the reflector is directeddownwardly, while an opposing, smaller top portion 39 is directedupwardly. A plurality of LEDs 32 are oriented downwardly at an inwardangle, and are aimed toward complementary reflecting surfaces 24 ofreflector 22. A heat sink 40 atop lens 14 provides both a mounting pointand a cooling means for LEDs 32 and, optionally, any associated controlor driver electronics (not shown). Lens 14 provides protection for LEDs32 and reflector 22, shielding them from exposure to the elements.Mounting base 18 facilitates installation of lighting system 10 at adesired site.

LEDs 32 may be any type of light emitting diode suitable for use withlighting system 10. As a non-limiting example, LEDs 32 may be arrangedin a linear or non-linear array (FIG. 2), and may be packed in groups orsub-groups having a predetermined number of LED elements. In oneembodiment of the present invention LEDs 32 are oriented to extenddownwardly from heat sink 40 and are aimed inwardly (i.e., generallytoward central axis 36) at an angle of about 45 degrees as discussedabove, though greater and lesser angles are anticipated within the scopeof the invention.

By positioning LEDs 32 in the manner shown in FIG. 9 a beam of light 42emitted by the LEDs is directed toward a focusing area of reflector 22,so the beam is relatively tightly focused. In addition, heat sink 40substantially blocks undesired light emissions from LEDs 32 in anupwardly direction from lighting system 10, thereby limiting lightpollution generated by the lighting system in the upward direction fromthe lighting system. Similarly, directly-emitted light from LEDs 32 islimited by reflector 22 and housing 16 to block light emitted by LEDs 32from traveling in a downwardly direction from lighting system 10.

In some embodiments of the present invention LEDs 32 are mounted ondetachable, insulated metal substrates 44 to form light sourceassemblies that easily plug into mating connectors situated in lightingsystem 10. Such non-leaded assemblies reduce the labor associated withreplacing the LEDs and eliminate service problems associated withwire-lead breakage.

For example, substrates 44 may include a connector portion 46A that isconfigured to electrically and mechanically couple to a mating connector46B mounted to heat sink 40. Connectors 46A, 46B are preferablyselectably detachable. Thus, in the event that one or more substrates 44are replaced, heat sink 40 may be detached from lighting system 10 byremoving a fastener 48 from a threaded receptacle in housing 16 toexpose substrates 44. The select substrates 44 are detached from theirrespective mating connectors 46B and replaced. Once the selectsubstrate(s) 44 are replaced, heat sink 40 is placed onto lightingsystem 10 and fastener 48 is re-installed, securing the heat sink to thelighting system.

In some embodiments of the present invention lighting system 10 includesat least one auxiliary lighting assembly having one or more auxiliaryLEDs 50, preferably configured to emit light upwardly from lightingsystem 10. In some embodiments auxiliary LED 50 may differ from LEDs 32.For example, auxiliary LED 50 may be configured to emit infrared lightto alert flight crews operating with night vision imaging systems(NVIS).

A method of using optic 12 or lighting system 10 includes arranging aplurality of reflecting surfaces 24 relative to each other, thereflecting surfaces having a linearly-projected cross-section 28. Themethod also includes the step of positioning at least one LED 32relative to at least one of the reflecting surfaces 24, the positioningstep angling the central light-emitting axis 30 of the LED relative tothe optical axis 34 associated with the reflecting surface 24 at about45°. The method also comprises transmitting light from LED 32 to thereflecting surface 24. In one embodiment of the method, the about 45°has a tolerance of ±15°.

In one embodiment of the method, the at least one LED 32 comprises aplurality of LEDs, the at least one optical axis 34 comprises aplurality of optical axes, and the positioning step comprisespositioning each of the plurality of LEDs relative to a respective oneof the plurality of optical axes 34 at about 45°. In one embodiment ofthe method, each reflecting surface 24 comprises a cross-sectionprojected along a linear axis 28, and the arranging step comprisesarranging the plurality of reflecting surfaces 24 relative to each otherso that a plurality of the linear axes are angled relative to eachother.

With reference to FIG. 10, lighting system 10 may include a controlsystem 52 that may be configured (or reconfigured) as desired to suit aparticular installation. In some embodiments control system 52 includesa controller 54. Controller 54 may be a digital microprocessor-basedcontrol unit configured to receive input signals and process sameaccording to control logic to control the operation of lighting system10. Alternatively, controller 54 may comprise other digitalarchitectures utilizing, for example, a computer, microcontroller,programmable logic device and the like. The control logic of controller54 may be defined by a set of predetermined instructions, such as acomputer program or “fuzzy logic.” In other embodiments of the presentinvention portions of controller 54 may be analog, such as an analogopen- or closed-loop control system. Controller 54 may be a separate,standalone component or made integral with (or distributed about)lighting system 10, such as housing 16 and heat sink 40.

A driver 56 of control system 52 controls the operation of LEDs 32, 50,controlling the voltage and/or current supplied to the LEDs, anddetecting and compensating for faults within the LEDs. Driver 56 mayalso control the flash rate of LEDs 32, 50 in accordance with controlsignals provided by controller 54. Furthermore, when LEDs 32, 50 are tobe turned off driver 56 may remove power supplied to the LED inaccordance with control signals provided by controller 54.

Control system 52 may utilize a local or remote global positioningsatellite (GPS) receiver 58, a clock 60, and so on to determine sundownand sunup to automatically turn lighting system 10 on and offaccordingly and/or control the brightness of the output light via driver56. In one embodiment of the present invention an ambient light sensor62 may be utilized for this purpose, providing to controller 54 anelectrical signal corresponding to the level of ambient light proximatelighting system 10. Ambient light sensor 62 may likewise be used as acontrol signal for control system 52 to dim the light output from LEDs32 during periods of low-light, such as during inclement or overcastweather. Communication link 64 may also be connected to wired andwireless analog or digital networks including, without limitation, localarea networks, wide area networks and the Internet.

Control system 52 may also include a one-way or two-way communicationlink 64 to facilitate remote control and monitoring of the status andoperation of lighting system 10. Communication link 64 may include oneor more of a radio frequency or light-based communication link.

In some embodiments of the present invention lighting system 10 mayinclude an Automatic Dependent Surveillance-Broadcast (ADS-B)surveillance system 66 to detect aircraft equipped with ADS-Bcapability. ADS-B is an anti-collision technology being adopted byaircraft operators to provide airborne collision avoidance capability.ADS-B is the linchpin technology of the Federal AviationAdministration's (FAA's) current “NextGen air traffic managementsystem.” ADS-B is intended to enable the FAA to safely increase thedensity of air traffic while simultaneously reducing aircraft fuelconsumption, allowing more dynamic and direct routing, improvinganti-collision capability in aircraft, and enabling information exchangewith airborne aircraft. At the core of the ADS-B system is a “heartbeat”that is transmitted by outfitted aircraft providing the aircraft'sidentification, location, velocity, and other relevant state data.Ground-based and airborne ADS-B receivers can receive this heartbeat andaccurately determine an aircraft's position, direction, and velocity ina timely manner.

ADS-B system 66 may include sensing apparatus within or proximate tolighting system 10 to detect “targets,” i.e., vehicles in the vicinityof a predetermined area, or an object or structure and then generatedata relating to the targets. Alternatively, ADS-B system 66 may receivetarget data from sources remote from lighting system 10, either directlyor via communication link 64. In various embodiments of the presentinvention ADS-B system 66 may utilize, without limitation, radar, sonarand proximity sensors to generate target data. ADS-B system 66 may alsoutilize information obtained on the Internet to generate target data.ADS-B system 66 may include or utilize any type of system, device orapparatus now known or later invented having a target detectioncapability. ADS-B system 66 is thus configured to detect at least onetarget vehicle.

With reference to FIGS. 9 and 10 together, in some embodiments of thepresent invention the illumination characteristics of lighting system 10may be altered by control system 52 to correspond to the level of thethreat of a collision. For example, light emitted by lighting system 10may be increased in brightness and/or its flash rate may be increased asa target vehicle approaches an associated predetermined obstruction,then decreased in brightness and/or flash rate as the target moves awayfrom the obstruction. Similarly, an aural alerting signal 68, such as asiren, may be actuated and may increase in frequency as a target vehicleapproaches a predetermined obstruction, then decrease in frequency asthe target vehicle moves away from the obstruction. Lighting system 10may also be altered from a first color to a second color as a targetvehicle approaches a predetermined obstruction, then restored to thefirst color as the target vehicle moves away from the obstruction.Finally, if the control system 52 detects a target vehicle within apredefined hazard envelope, which may be one or more predetermined areasand altitudes, the control system may broadcast over radio frequency,wired or wireless networks, the Internet, or any other suitable media(using, for example, communication link 64) a warning (such as, forexample, an ADS-B compliant warning) to alert the target vehicle of apotential hazard.

Details of a collision avoidance system 100 are shown in FIG. 11according to an embodiment of the present invention. System 100 includesa sensor 102 for detecting potential threats, an awareness engine 104for evaluating detected potential threats, and an alerting system 106 towarn vehicles of obstacles. A communication interface 108 provides forinformation flow to and from system 100, and a control 110 controls theoperation of the various elements of the system in a predeterminedmanner.

Sensor 102 provides the detection ability of collision avoidance system100. Sensor 102 may include sensing apparatus within and/or proximate tosystem 100 to detect “targets,” i.e., vehicles in the vicinity of apredetermined area, object or structure and then generate data relatingto the targets. In one embodiment sensor 102 may include an AutomaticDependent Surveillance-Broadcast (ADS-B) surveillance system to detectaircraft equipped with ADS-B capability. Sensor 102 may also receivetarget vehicle information from sources remote from system 100, eitherdirectly or via communication interface 108 and generate target data atleast in part from these sources. In various embodiments of the presentinvention sensor 102 may include or utilize any type of system, deviceor apparatus now known or later invented having a target detectioncapability. Examples include, without limitation, radar, sonar andproximity sensors. Sensor 102 may also utilize information obtained onnetworks such as the Internet to generate target data. Sensor 102 ispreferably configured to detect at least one target vehicle in apredetermined area and to generate target data relating to the targetvehicle (or vehicles). Target data generated by sensor 102 is providedto awareness engine 104.

In some embodiments of the present invention sensor 102 may comprise aplurality of target detection devices of the same or differing types inorder to increase the fidelity of the detection capability of system100. In such cases it may be preferable to configure sensor 102 toanalyze and integrate the data from plural sensors into composite targetdata before providing the target data to awareness engine 104.

Details of awareness engine 104 are shown in FIG. 12 according to anembodiment of the present invention. Target data 112 (which mayrepresent one or a plurality of target vehicles) generated by sensor 102is provided to an evaluation subsystem 114, which may comprise analogand/or digital control components and predetermined instructions similarto controller 54, detailed above.

In the case of a plurality of targets, evaluation subsystem 114determines, from corresponding target data, the risk of a collisionbetween two or more targets in the form of evaluation results 116provided to alerting system 106. If the risk of the evaluation resultsexceeds a predetermined threshold, alerting system 106 is activated toissue a warning. Evaluation results 116 may, in addition to determiningthe risk level, provide ancillary data such as a graded level of risk(e.g., low, moderate, high), whether the risk of a collision isincreasing or decreasing, and timing aspects of the risk (e.g., the rateat which the risk is increasing or decreasing, immanency of collision,etc.).

Similarly, evaluation subsystem 114 may compare target data relating toone or a plurality of targets with predetermined obstruction data 118and provide evaluation results 116 in the manner detailed above.

Awareness engine 104 provides system 100 with the ability to interpretsensor 102 target data, determine if there is a threat of a collisionand, if there is a potential threat, cause alerting system 106 to take apredetermined action. Awareness engine 104 receives target data 112 fromsensor 102, evaluates the target data and determines if further actionis required, and provides to alerting system 106 commands regarding whataction is required. Awareness engine is preferably implemented utilizingrelatively robust computing hardware and software, and in someembodiments may be an embedded system (i.e., a purpose-designedcomputing system and associated interfaces).

With reference again to FIG. 11, alerting system 106 is configured toperform the function of alerting a vehicle (or vehicles) of a potentialcollision risk. Alerting system 106 is preferably configured to receivecommands from awareness engine 104 and to act in a timely manner basedon the commands to avoid a collision. In one embodiment of the presentinvention alerting system 106 is an anti-collision light. In variousembodiments alerting system 106 may include one or more of any devicesand methods suitable for alerting vehicle operators of a potentialcollision. Examples include, without limitation, lights, sounds, andmovement. Alerting system 106 may also alert vehicle operators byvarious electronic communications methods such as emails, short messageservice (SMS) alerts, injecting the collision information into theInternet for use by downstream services, and radio alerts.

In some embodiments of the present invention the characteristics ofalerting system 106 may be adjusted to correspond to the level of thethreat of a collision. For example, an anti-collision light of thealerting system (and/or lighting system 10) may be regularly increasedin brightness and/or flash rate as a target vehicle approaches anassociated predetermined obstruction, then decreased as the targetvehicle moves away from the obstruction. Similarly, an aural signal,such as a siren, may be increased in frequency as a target vehicleapproaches a predetermined obstruction, then decreased as the targetvehicle moves away from the obstruction. Lighting system 10 and/or otherlight emitting devices may also be altered from a first color to asecond color as a target vehicle approaches a predetermined obstruction,then restored to the first color as the target vehicle moves away fromthe obstruction.

Communication interface 108 facilitates communications to and, in somecases, from system 100. The communications may include receiving datafrom sources external to system 100 including, but not limited to, datarelating to targets, control signals, commands, fault corrections, andinstruction or program updates to control 110. The external sources mayinclude, but are not limited to, computing devices, wired and wirelessnetworks, proprietary information-collecting devices, the Internet,radio receivers, and so on. Such external sources may be located nearsystem 100, or may be remote from the system and coupled to the systemby any communication means now known or later invented. Communicationinterface 108 may also be configured to transmit external to system 100status information relating to the system, including fault information.Communication interface 108 may be variously configured to receiveand/or transmit analog signals as well as digital data, and may beconfigured to communicate using any data protocol or standard now knownor later developed.

Control 110 is configured (or configurable) to control the operation ofthe components of system 100 in a predetermined manner to achieve thedesired result of collision avoidance. Control 110 may be configuredwith analog and/or digital components, such as any type of computingdevice now known or later developed. Example computing devices include,without limitation, digital and/or analog computers, processors,microprocessors and microcontrollers. Control 110 may further include apredetermined set of instructions, generally termed “software,” toconfigure the operation of control 110 and, in turn, system 100. Control110 may also include a memory portion to store said software and, insome cases, data such as computations, historical logs, records, targetvehicle information, and so on. It will be understood that control 110may be a discrete subsystem as shown in FIG. 11, or may be distributedamong some or all of sensor 102, awareness engine 104, alerting system106 and communication interface 108. In still other embodiments system100 may include both a discrete control subsystem 110 and distributedcontrol elements, the control subsystem and distributed control elementsworking either independently or in concert with one another.

In some embodiments of the present invention sensor 102, awarenessengine 104, alerting system 106, communication interface 108 and control110 may be modularized and interconnected with standard or proprietaryinterfaces. In this manner, system 100 may be easily modified orupgraded by replacing individual modules with improved or modifiedmodules. For example, a particular system 100 may be altered fromutilizing an alerting system 106 having a high-intensity light as ananti-collision device to an alerting system having an auralanti-collision device with a simple exchange of the modularized alertingsystem subcomponent portions.

In addition, system 100 may be configured to be extensible so that, ifmore than type of alerting system 106 is desired the system can beupgraded to include multiple devices while maintaining the same sensorand potentially the same awareness engine 104. Similarly, system 100 maybe configured to accommodate a plurality of sensors 102 and/or types ofsensors to detect targets.

As an example of the operation of system 100, sensor 102 may include anADS-B surveillance system. ADS-B data relating to the location andvelocity of a nearby vehicle is received by sensor 102, and is providedto awareness engine 104 by the sensor. Awareness engine 104 analyzes thedata to determine if the vehicle poses a threat of collision with apredetermined obstruction or obstructions. If such a threat is detected,alerting system 106, such as a warning light, is activated to emitsuitable warnings and/or its operating characteristics altered in apredetermined manner, such as altering its brightness, on-off pattern,etc., in a manner calculated to alert the vehicle of the impendingdanger. This merging of ADS-B with anti-collision devices issignificantly more effective at preventing collisions, therebyincreasing the safety of navigation.

Similarly, sensor 102 may be configured to receive radar data as asensor input for both airborne and maritime systems to detect potentialcollision threats. In this embodiment, radar data from sensor 102provided to awareness engine 104 allows the awareness engine todetermine if a vehicle poses a collision threat. If such a threat isdetected, alerting system 106, such as a warning light, is activated ina manner calculated to alert the vehicle of the impending danger.

Wired and wireless communication networks, including the Internet, mayalso be utilized as sources for sensor 102 information. For example,sensor 102 may, via communication interface 108, query the Internet forthe current (i.e., “real-time”) and projected locations of variousvehicles. Internet-derived target data is provided to awareness engine104 by sensor 102 and the awareness engine determines if a vehicle posesa threat of collision. If such a threat is detected, alerting system106, such as a warning light, is activated in a manner calculated toalert the vehicle of the impending danger.

As can be appreciated, the present invention is an “intelligent”collision avoidance system and, as such is an evolution of thetraditional passive anti-collision device. In contrast to such passivewarning lights, the present invention may include an alerting system 106having a visually perceivable indicator 134 (FIG. 13) such as lightingsystem 10 or other anti-collision or obstruction light alerting system.Indicator 134 is understood to include any type of “visuallyperceivable” indicator, including those outside the range of humanperception but visible with the aid of suitable equipment, such nightvision imaging systems (NVIS).

Thus, for example, an alerting system 106 such as an anti-collisionlight 134 may be commanded to alter one or more of its operatingcharacteristics (e.g., brightness, intensity, direction, flash rate,flash pattern, etc.) in the event of a potential collision detected bysensor 102 and evaluated by awareness engine 104. With system 100, nolonger is collision avoidance solely dependent on an observer operatinga vehicle proximate an associated obstructing structure. The presentinvention couples target-detection sensing capabilities withanti-collision warning devices, thereby making the present invention anactive participant in collision avoidance. In the aforementioned system100 wherein sensor 102 includes an ADS-B surveillance system, the systemenables an alerting system 106 such as an anti-collision light toexhibit operating characteristics that are dependent upon the real-timerisk of potential collisions.

The present invention is not limited to warning vehicles of potentialcollision hazards with structures such as buildings and communicationtowers. In fact, the present invention provides collateral capabilitybeyond collision avoidance. An example of such collateral capabilitiesprovided by the present invention includes traffic density alerts,whereby the lighting characteristics of airport lighting may be changeddepending on the density of local traffic.

As another example, the present invention may be used for proximityreporting. With the ability to monitor traffic in close proximity, thepresent invention may be configured to monitor and report vehicles thatclose within a specified proximity. This aids to identify potentiallydangerous situations and reduce the potential of a collision.

As yet another example, the present invention may be used to protectrelatively mobile hazards from collisions by vehicle. Aviation databasesare not updated in real-time. Consequently, relatively mobile,impermanent, obstacles are not typically included in aviation obstacledatabases which are normally updated only every 28 days. Incorporatingan ADS-B transceiver into sensor 102 of system 100 provides essentiallythe same functionality as updating the obstacle databases, effectivelyinjecting the location of mobile obstacles into an aircraft's onboardanti-collision system.

Further details of example embodiments of the present invention aredescribed below. These examples merely describe exemplary embodimentsand are not intended to be limiting in any way.

Intelligent Runway Anti-Intrusion System (IRAS)

Perhaps the most challenging problem the FAA currently faces is reducingincidents of runway incursions. Replacing the taxiway identificationlights at a runway “hold short” threshold (i.e., an aircraft runwayground staging point) prior to entering the runway, with intelligentanti-collision lighting within the scope of the present inventionprovides a way to reduce the number of runway incursion incidents. TheIRAS comprises a system 100 incorporating a sensor 102 having ADS-Bsurveillance capability and an awareness engine 104. The ADS-B equippedsensor 102 and awareness engine 104 monitor for aircraft within aspecified distance (such as, for example, about twice the length of therunway and within about 400 feet above the ground/touchdown zone height)and moving at a speed greater than about 40 knots. These distance andvelocity variables, which may be made adjustable, enable the IRAS todetermine if there are aircraft on the runway, departing, or arrivingand then alter the operating characteristics of taxiway lighting toalert taxiing aircraft of the presence of aircraft on the runway. TheIRAS does not require additional infrastructure and can utilize thepre-existing power provided to the taxiway lighting. No communicationsto the IRAS is required, as the ADS-B transceiver is self contained.

Operationally, the IRAS only changes state when there is a potentiallyconflicting aircraft in the runway environment; otherwise the light is adefault color and intensity for normal taxiway lighting. When a pilottaxis up to the runway hold short threshold and no aircraft are presentin the runway environment the IRAS will be the default taxiway color(i.e., blue) and intensity. However, if there is an aircraft in therunway environment the IRAS may change color (i.e., to red, forexample), and/or start blinking if the aircraft in the runwayenvironment poses a collision threat to the taxiing aircraft.

Intelligent Tower Anti-Collision Lighting (ITAL)

Current tower obstacle lighting typically consists of a flashing lightof a specified intensity, interval, and color. The light does not havethe capacity to alter its operating characteristics based on theproximity of aircraft. Incorporating “intelligence” into tower lightingenhances the effectiveness of anti-collision tower lighting. Withreference to FIGS. 11 through 13 together, a tower 120 includes acollision avoidance system 100 according to an embodiment of the presentinvention. System 100 includes an alerting system 106 mounted to tower120, shown in FIG. 13 as an obstruction light 134.

An ADS-B navigation system 121 comprises a satellite navigation system122, such as a Global Navigation Satellite System (GNSS). Aircraftutilizing the ADS-B system, such as aircraft 124, 126, generateinformation relating to their current position based upon signals 128from satellite navigation system 122. Aircraft 124, 126 broadcast theirposition information, as at 130, 132. The position information 130 ofaircraft 124 may be received by aircraft 126. Likewise, positioninformation 132 of aircraft 126 may be received by aircraft 124. Eachaircraft is thus provided with position information relating to theother aircraft. In addition, system 100 receives position information130, 132 relating to aircraft 124, 126 respectively via sensor 102. Theposition information is provided to awareness engine 104, whichdetermines whether a threat of a collision between either of aircraft124, 126 with tower 120 exists. If it is determined that a threatexists, alerting system 106 is activated in a predetermined manner toalert the aircraft.

In one embodiment, the anti-collision tower light 134 of alerting system106 may be controlled in such a manner to change its operating statefrom standard collision avoidance variables (e.g., color, intensity,flash frequency) to an alert condition which will alert pilots that theyare too close to the tower. The alert condition may be one or more of achanged color, increased intensity, and increased flash frequency. Theon-off duty cycle of indicator 134 may also be altered to draw attentionto the obstruction 120 including, but not limited to, Morse codesignals.

In some embodiments of the present invention system 100 may directlyalert the aircraft 124, 126 to the presence of an obstacle such as tower120. In this embodiment, tower 120 will not continuously broadcast itslocation, but rather will only broadcast an alert when a detectedaircraft is determined to be at risk of a collision with the tower. Whenan aircraft is at risk the ITAL system may alert the aircraft via ADS-Busing alerting system 106 and/or communication interface 108 in anymanner previously described.

Intelligent Mobile Obstruction Lighting (IMOL)

Databases containing information relating to obstacles to aviation arenormally updated every 28 days. Between these updates it is incumbentupon the pilot to obtain obstacle updates via the Notices to Airmen(NOTAM system) administered by the FAA. A drawback of the NOTAM systemis that it is not always reliable for delivering timely obstacleinformation to pilots. Furthermore, there is no reasonable method toupdate pilots in real-time of changes to obstacles while airborne. Thus,relatively “mobile” obstacles (e.g., movable stationary obstacles,repositionable obstacles, and moving obstacles), such as large cranes,present a unique challenge to this system. Such obstacles may not be ina given location for a sufficient period of time to be added to anobstacle database, or they may be moved subsequent to being added to thedatabase. An Intelligent Mobile Obstruction Lighting (IMOL) systemovercomes these drawbacks with a collision avoidance system 100 having asensor 102 that includes an ADS-B system 121. With system 100incorporated with such obstacles the transient and mobile nature of theobstacle is not a limitation to alerting aircraft to potential collisionthreats. Using ADS-B system 121 the IMOL system may detect aircraft inclose proximity to the obstacle and change the state of alerting system106 in any manner previously described to alert the aircraft, includingissuing a warning via ADS-B signals transmitted to the aircraft as aterrain alert.

Intelligent Directed Lighting (IDL)

The proliferation of obstructions such as towers and the associatedhazard lighting has reduced the effectiveness of the lighting by makingit commonplace. Pilots are thus accustomed to seeing a plurality ofobstacle lights and may not register particular obstruction lights as anindication of an imminent hazard in time to avoid a dangerous situation.By adding “intelligence” to a collision avoidance system an alertingsystem 106 incorporating an anti-collision light 134 may be configuredto alter its operating characteristics in a predeterminedattention-getting manner and thus attract the attention of a pilot. Inaddition to changing one or more of the intensity, color, flash rate andon-off duty cycle of an anti-collision light, a visually perceivablelight may be aimed or otherwise directed at an aircraft and, optionally,the intensity increased in order to alert an aircraft of a risk ofcollision. Using a sensor 102 equipped with ADS-B the awareness engine104 of system 100 in the IDL is able to determine the azimuth,elevation, and range to a target aircraft. The IDL utilizes this targetinformation to cause alerting system 106 to aim or direct a focused beamof high-intensity light at the intruding aircraft to alert the aircraftof an impending collision. Alerting system 106 may comprise, withoutlimitation, a gimbaled light, mechanical, electro-mechanical, electricaland electronic positioning devices to aim a light in a determinablemanner, light-focusing devices, and selectively actuated lights.

System 100 is capable of providing sophisticated functionality byintegrating emerging technologies into a novel system for the benefit ofthe traveling public. This integration is consistent with standarddevelopment and integration of object orientated endeavors providing amodular, scalable, and reliable system. Strong, clear interfaces arepreferably maintained between the hardware and software modules tofurther enhance the modularity of the system.

With reference to FIG. 13, ADS-B system 121 relies upon satellite-basedglobal positioning system (GPS) navigation equipment on board anaircraft to determine the aircraft's precise location in space. Thislocation information may be combined with other information such as thetype of aircraft, its speed, its identification number, and whether theaircraft is turning, climbing, or descending. The information is thenbroadcast by the aircraft several times a second in an “ADS-B Out”transmission. Other aircraft and ground stations that are equipped with“ADS-B In” receivers and within range (typically about 150 miles)receive these ADS-B Out broadcasts. The ground stations may combine theADS-B Out broadcasts received from different local area aircraft withadditional location information received from, for example, ground radardata relating to non-ADS-B equipped aircraft, and rebroadcast the dataout to aircraft in the area as air traffic information. The air trafficinformation, along with other information sent by the ground station,such as weather information, may then be displayed in the cockpits ofaircraft that are equipped with ADS-B In receivers.

From the foregoing, it is apparent that ground stations form a keyelement of the ADS-B system 121. However, ADS-B ground stations arelacking in many remote areas having little infrastructure or relativelylow levels of aircraft traffic. Likewise, a less-than-desirable numberof ADS-B ground stations are found in areas with adverse terrain, suchas mountainous and desert areas. On the other hand, it is not uncommonto find communications systems and obstruction lighting systems in manyof these remote areas.

With reference to FIGS. 14 and 15, in one embodiment of the presentinvention an alerting system 106 in the form of an obstruction light 134is configured to include a sensor 102 in the form of an ADS-B groundstation 200. Details of ground station 200 are shown in FIG. 15according to an embodiment of the present invention. As shown, groundstation 200 includes a receiver 202, a transmitter 204, a communicationinterface 206 and an ADS-B processor 208.

Receiver 202 may be any type of receiver configured to receive ADS-B Outtransmissions. In United States airspace, ADS-B In and Out informationis available on two separate frequencies, 1090 MHz and 978 MHz. The 1090MHz frequency is used by Mode-S transponders, and when a transponder isequipped with compliant hardware and software (an ADS-B approved versionof “ES” or “Extended Squitter”), the transponder itself acts as an ADS-Btransceiver. The 978 MHz frequency, sometimes referred to as a “UAT”(Universal Access Transceiver), is the frequency reserved for aircraftflying below Fight Level 180; it has a much higher bandwidth than 1090MHz (the frequency is far less congested) and, therefore more data canbe transmitted to the aircraft from the ground.

In airspace other than the United States, the 978 MHz frequency is notcurrently authorized for use in ADS-B. Due to congestion problems,however, this restriction may be lifted in the future.

Transmitter 204 may be any type of transmitter suitable for transmittingADS-B signals to ADS-B In receivers.

Communication interface 206 facilitates communications to and, in somecases, from system 200. The communications may include receiving datafrom sources external to the system including, but not limited to, data(such as radar data relating to targets, weather data, etc.), controlsignals, commands, fault corrections, and instruction or programupdates. The external sources may include, but are not limited to,computing devices, wired and wireless networks, proprietaryinformation-collecting devices, the Internet, radio receivers, and soon. Such external sources may be located near system 200, or may beremote from the system and coupled to the system by any communicationmeans now known or later invented. Communication interface 206 may alsobe configured to transmit to external sources status informationrelating to system 200, including fault information. Communicationinterface 206 may be variously configured to receive and/or transmitanalog signals as well as digital data, and may be configured tocommunicate using any data protocol or standard now known or laterdeveloped.

ADS-B Processor 208 receives target data from receiver 202 and anyrelevant data from any applicable external sources via communicationinterface 206. The data are processed in a predetermined manner togenerate an ADS-B ground station signal containing, without limitation,aircraft traffic alerts, terrain hazard alerts, and weather information.The ADS-B ground station signal is broadcast via transmitter 204 forreception by ADS-B In receivers of the target vehicles.

In various forms of ground station 200, some (or portions) of one ormore of receiver 202, transmitter 204, communication interface 206 andADS-B processor 208 may be located remote or external to alerting system106. In addition, receiver 202 and transmitter 204 may be combined toform a transceiver.

With reference to FIG. 16, in still another embodiment of the presentinvention an ADS-B transmitter 204 may be integrated with an alertingsystem 106 such as an anti-collision light 134 and configured tocontinuously transmit, thereby marking in ADS-B system 121 (FIG. 13) theobstacle to which the anti-collision light is mounted. In this mannerthe obstacle is displayed as a terrain alert in the cockpit of nearbyaircraft. Alerting system 106 may also be configured such that at leastone of its operating characteristics is altered in the event of adetected threat of a collision by system 100, as detailed above.

With continued reference to FIGS. 14 and 15, in an alternate embodimentground station 200 may be configured to function as a repeater. When soconfigured, receiver 202 receives an ADS-B signal. Ground station 200,additionally utilizing ADS-B processor 208 as a repeater controller,re-transmits the received ADS-B signal with transmitter 204. There-transmitted ADS-B signal may be re-transmitted by transmitter 204 ata relatively high level, thereby extending the effective range of theoriginal ADS-B signal. When functioning as a repeater, ground station200 may often take advantage of the relative height of an associatedtower 120 to forward the received ADS-B signal. For example, groundstation 200 may be located at or near the top of tower 120, and mayoptionally be integrated with an indicator 134 such as an obstructionanti-collision light. Alternatively, ground station 200 may be locatedat a base mount 210, with transmitting and receiving antennae 212remotely located at or near at or near the top of tower 120. Thetransmitting and receiving antennae 212 may also be integrated with anindicator 134, if desired. The repeater function of ground station 200may be utilized to extend ADS-B coverage into relatively remote areasand/or overcome obstacles that would otherwise limit the range of theADS-B signal.

While this invention has been shown and described with respect to adetailed embodiment thereof, it will be understood by those skilled inthe art that changes in form and detail thereof may be made withoutdeparting from the scope of the claims of the invention. For example,although the disclosed invention is described in terms of use as anobstruction light for the purpose of illustration, one skilled in theart will appreciate that the disclosed invention may be utilized toadvantage in any suitable type of lighting and collision alertingsystems.

What is claimed is:
 1. A collision avoidance system, comprising: asensor adapted to: detect at least one vehicle in a vicinity of apredetermined area, and generate target data relating to the at leastone vehicle; an awareness engine adapted to: receive the target datafrom the sensor, and evaluate the target data for a threat of acollision; and an alerting system adapted to alert the at least onevehicle in the event of a threat of a collision, the alerting systembeing activated by the awareness engine.
 2. The collision avoidancesystem of claim 1 wherein the sensor is configured to detect AutomaticDependent Surveillance-Broadcast (ADS-B) signals transmitted by the atleast one vehicle.
 3. An airport traffic collision avoidance system,comprising: a vehicle sensor configured to: detect a signal transmittedby at least one vehicle in a vicinity of a predetermined area of anairport, use the detected signal to determine at least one of aposition, direction, and velocity of the vehicle, and generate a targetdata relating to the at least one vehicle; an awareness engine adaptedto: receive the target data from the sensor, and evaluate the targetdata for a threat of a collision with another ground or airbornevehicle, or an obstruction; and an alerting system adapted to: receive acommand from the awareness engine, and alert the at least one vehicle inthe event of a threat of a collision in the predetermined area, thealerting system being selectably activated by the command from theawareness engine.
 4. The airport traffic collision avoidance system ofclaim 3 wherein the awareness engine comprises an evaluation subsystem,the evaluation subsystem being adapted to: receive the target data,determine a risk of a collision with the at least one vehicle, andprovide evaluation results to the alerting system.
 5. The airporttraffic collision avoidance system of claim 4, wherein the at least onevehicle comprises a plurality of vehicles, the evaluation subsystembeing further adapted to determine, from corresponding target data, therisk of a collision between the vehicles.
 6. The airport trafficcollision avoidance system of claim 4 wherein the alerting system isactivated to issue a warning when the risk of a collision exceeds apredetermined threshold.
 7. The airport traffic collision avoidancesystem of claim 3 wherein the alerting system further comprises avisually perceivable indicator.
 8. The airport traffic collisionavoidance system of claim 7 wherein at least one operatingcharacteristic of the indicator is altered in the event of a threat of acollision.
 9. A collision avoidance system for a movable obstacle,comprising: a sensor configured to: detect a signal transmitted by atleast one vehicle in a vicinity of a predetermined area of a movableobstacle, use the detected signal to determine at least one of aposition, direction, and velocity of the vehicle, and generate a targetdata relating to the at least one vehicle; an awareness engine adaptedto: receive the target data from the sensor, and evaluate the targetdata for a threat of a collision with the movable obstacle; and analerting system adapted to: receive a command from the awareness engine,and alert the at least one vehicle in an event of a threat of acollision with the movable obstacle, the alerting system beingselectably activated by the command from the awareness engine.
 10. Thecollision avoidance system of claim 9 wherein the awareness enginecomprises an evaluation subsystem, the evaluation subsystem beingadapted to: receive the target data, determine a risk of a collisionwith the at least one vehicle, and provide evaluation results to thealerting system.
 11. The collision avoidance system of claim 10, whereinthe at least one vehicle comprises a plurality of vehicles, theevaluation subsystem being further adapted to determine, fromcorresponding target data, the risk of a collision between the vehicles.12. The collision avoidance system of claim 10 wherein the alertingsystem is activated to issue a warning when the risk of a collisionexceeds a predetermined threshold.
 13. The collision avoidance system ofclaim 9 wherein the alerting system further comprises a visuallyperceivable indicator.
 14. The collision avoidance system of claim 13wherein characteristics of the indicator are altered in a predetermined,visually perceivable manner.
 15. The collision avoidance system of claim14 wherein an intensity of the indicator is altered by the alertingsystem in the event of a threat of a collision with the movableobstacle.
 16. The collision avoidance system of claim 14 wherein a colorof the indicator is altered by the alerting system in the event of athreat of a collision with the movable obstacle.
 17. The collisionavoidance system of claim 14 wherein a flash rate of the indicator isaltered by the alerting system in the event of a threat of a collisionwith the movable obstacle.
 18. The collision avoidance system of claim14 wherein an on-off duty cycle of the indicator is altered by thealerting system in the event of a threat of a collision with the movableobstacle.
 19. The collision avoidance system of claim 14 wherein theindicator is aimed or directed in a predetermined manner in the event ofa threat of a collision with the movable obstacle.
 20. The collisionavoidance system of claim 14 wherein an intensity of the indicator isincreased in the event of a threat of a collision with the movableobstacle.